Folding case with rotating side cover

ABSTRACT

The present invention relates to a protective case for foldable mobile devices. The folding case according to the present invention comprises a first case and a second case, wherein the folding case further comprises a side cover which rotates by an elastic part as the foldable mobile device is folded or unfolded, and provides a full protection for the entire foldable mobile device including each corner of its hinge part. The folding case according to the present invention covers the hinge part smoothly without any unfavorable space or gap, and it provides the satisfaction with the use and the beauty of the overall appearance as the users would conceive that the two separated case parts and the hinge part operates as if those parts form one united case.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. provisional patent applicationNo. 62/511,280, filed on Sep. 29, 2020, the disclosures of which areincorporated herein by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to a protective case for electronicdevices such as mobile smart phones and cellular phones. Specifically,the present invention relates to such protective cases for foldablemobile electronic devices.

BACKGROUND OF THE INVENTION

A mobile electronic device is a computing device that users are able tocarry all the time. Since the users carry a mobile device for theirdaily life, it is prone to be damaged due to their careless treatmentsand unintentional drops. Thus, protective cases for mobile electronicdevices have been widely used to minimize the damage. Such protectivecases generally protect the mobile electronic device from the outsideimpact by embracing the exterior of the device with the shell-likestructure of the case components.

A typical display system for a mobile electronic device has adopted aflat panel display. However, a flexible display has been recentlydeveloped, which enables a screen to be folded or bent, and applied tomobile electronic devices. If the flexible display is applied to themobile electronic device, the device itself can be folded or bentaccordingly. Since the foldable mobile electronic device could providevarious innovative applications by its shape transition, there has beena growing expectation in the IT (Information Technology) industry.

However, one of the disadvantages of the foldable mobile device is thatit is hard to install a protective case thereon due to the shapetransition by the flexible display being folded or bent. In other words,the case may be easy to be installed on the non-transitionable portionof the foldable mobile device, whereas the case may be difficult to beinstalled on the transitionable portion due to its shape transition.

Since the cases currently available are difficult to be placed on thefoldable mobile device, especially on its hinge part which enables thefoldable mobile device to be folded or bent, it is hard to provide afull protection to the device from outside impact. In particular, sincethe hinge part is one of the most fragile components of the foldablemobile device, a case that protects the hinge part and the overalldevice regardless of the shape transitions is required to provide userswith the full protection of the foldable mobile device.

There is a case system commercially available that is designed toprotect a foldable mobile device, including the hinge part, byconnecting two separated case parts with an elastic linear protectivecomponent. However, the elastic linear protective component between twocase parts does not fit tightly to the hinge part depending on theposition of the flexible display of the foldable mobile device. If itdoes not fit tightly, the full protection of the foldable mobile device,the hinge part thereof in particular, cannot be achieved. Besides, thosetwo case parts are not assembled in a smooth way, and it fails toprovide the satisfaction with the use and the beauty of the overallappearance. Furthermore, each corner of the hinge part is notsufficiently covered by the elastic linear component, so that the fullprotection of the foldable mobile device could not be assured.

SUMMARY OF THE INVENTION

The folding case according to the present invention comprises a firstcase and a second case, wherein the folding case further comprises aside cover which rotates from a first position to a second positionaround the rotation axis of the first case, and an elastic part whichprovides an elastic force for the side cover to return to the firstposition. The side cover rotates as the foldable mobile device is foldedor unfolded.

The present invention provides a full protection for the entire foldablemobile device including each corner of its hinge part. The folding caseaccording to the present invention covers the hinge part smoothlywithout any unfavorable space or gap, and it provides the satisfactionwith the use and the overall aesthetic appearance as the users wouldconceive that the two separated case parts and the hinge part operatesas if those parts form one united case.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will become better understood with reference to theaccompanying drawings, wherein:

FIG. 1 demonstrates a representative foldable mobile device;

FIG. 2 shows a folding case according to an embodiment of the presentinvention;

FIG. 3 shows a folding case according to an embodiment of the presentinvention;

FIG. 4 shows representative features of a folding case according to anembodiment of the present invention;

FIG. 5 shows a first case and a side cover of a folding case accordingto an embodiment of the present invention;

FIG. 6 shows a first case and a side cover of a folding case accordingto an embodiment of the present invention;

FIG. 7 shows a bottom sectional view of a folding case according to anembodiment of the present invention;

FIG. 8 demonstrates a detailed connecting structure between a first caseand a side cover of a folding case according to an embodiment of thepresent invention;

FIG. 9 shows a support of a folding case according to an embodiment ofthe present invention;

FIG. 10 demonstrates steps of connection between a first case and a sidecover of a folding case according to an embodiment of the presentinvention;

FIG. 11 shows a folding case in a closed state according to anembodiment of the present invention;

FIG. 12 shows a folding case in an open state according to an embodimentof the present invention;

FIG. 13 shows a folding case in an open state according to an embodimentof the present invention;

FIG. 14 shows a bottom sectional view of a folding case according to anembodiment of the present invention;

FIG. 15 demonstrates that a side cover of a folding case is used as astand according to an embodiment of the present invention; and

FIG. 16 shows a button part of a folding case according to an embodimentof the present invention.

DETAILED DESCRIPTION EMBODIMENTS OF THE INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings, which form a part of this disclosure. It is to be understoodthat this invention is not limited to the specific devices, methods,conditions or parameters described and/or shown herein, and that theterminology used herein is for the purpose of describing particularembodiments by way of example only and is not intended to be limiting ofthe claimed invention.

The terms used in the description are to explain the embodiments, butnot to limit the present invention in any way. The term ‘comprise,’‘comprises,’ or ‘comprising’ is used to describe that a subject matteris constituted from a combination of features or characteristics. Thus,it should be understood that it does not exclude one or more additionalfeatures or the combination thereof.

FIG. 1 demonstrates a foldable mobile device (M). According to FIG. 1 ,the foldable mobile device (M) to which a folding case (C) is appliedaccording to an embodiment of the present invention comprises a firstbody (10), a second body (20) and a hinge part (30).

Each of the first body (10) and the second body (20) of the foldablemobile device (M) does not change its shape. The hinge part (30) is afeature that allows the foldable mobile device to be folded or bent.However, the hinge part (30) is prone to be damaged by the impact fromoutside. Therefore, it is important to keep the hinge part (30) safefrom the outside impact.

FIGS. 2 and 3 show a folding case (C) according to an embodiment of thepresent invention. According to FIGS. 2 and 3 , the folding case (C)according to an embodiment of the present invention comprises a firstcase (100), a second case (200), and side cover (300).

The first case (100) is installed on the first body (10) of the foldablemobile device (M). The first case (100) protects the foldable mobiledevice (M) with its width higher than one surface of the foldable mobiledevice (M). The first case (100) may comprise an edge part (110) whichcovers each corner of the first body (10). The edge part (110) protectsthe first body (10) with its width higher than one surface of the firstbody (10).

The edge part (110) according to an embodiment comprises a tunnel (111).The tunnel (111) is an aperture that is formed by at least a portion ofthe edge part (110) being opened or curved. The tunnel (111) is afeature to maintain that at least a portion of a surface of the firstcase (100) is not covered by the edge part (110). The edge part (110)embraces each corner of the first case (100), and covers a portion ofthe surface of the first case (100). If a speaker module is located inthe portion covered by the edge part (110), the sound from the speakermodule may not travel outside. If the tunnel (111) is established on thelocation of the edge part (110) that corresponds to the speaker module,the sound from the speaker module would travel through the tunnel (111).Accordingly, the sound from the foldable mobile device (M) can traveloutwards clearly without being covered by the edge part (110).

The second case (200) is installed on the second body (20) of thefoldable mobile device (M). The second case (200) protects the foldablemobile device (M) with its width higher than one surface of the foldablemobile device (M).

The second case (200) comprises a bulge part (210). The bulge part (210)is formed higher than the height of a camera module of the second body(20). If the camera module is located on the second body (20), it maycause scratches on the camera lens due to the height of the protrudedcamera module even with the protective case. The bulge part (210) isformed higher than the height of the camera module at the locationcorresponding to the camera module, and keeps the camera module safefrom scratches.

The side cover (300) protects the hinge part (30) of a foldable mobiledevice (M). According to FIG. 3 , the side cover comprises a patternpart. The pattern part plays a role in the non-slip function for theside cover (300) which has a round shape pattern for a better grip. Inan embodiment of the present invention, the pattern part may havevarious patterns, including a diagonal pattern, to achieve the non-slipeffect, but not limited thereto.

FIG. 4 shows representative features of a folding case according to anembodiment of the present invention. According to FIG. 4 , the sidecover (300) is connected to the first case (100). However, the firstcase (100) and the second case (200) may be separated. The previousfolding cases have a connecting part that connects two case parts toprotect the hinge part (30) of a foldable mobile device (M). In suchcases, two case parts are not connected smoothly due to the unfavorablegap over the connecting part when the folding case is unfolded, and thehinge part (30) cannot be properly protected. However, the presentinvention provides a case system that the first case (100) and thesecond case (200) are separated, and the side cover (300) connected tothe first case (100) rotates to protect the hinge part (30). Therefore,the structure of the present invention is completely different from theprevious folding case that has a connecting part to connect two caseparts.

The side cover (300) comprises a cover part (320) that covers up to thecorner of the hinge part (30) of the foldable mobile device (M). Theconnecting part of the previous cases could not protect the corners onthe side of the hinge part (30). However, the present invention safelyprotects the corners on the side of the hinge part (30) by the sidecover (300).

The folding case (C) according to an embodiment of the present inventioncomprises a pad part (500). The pad part (500) touches at least aportion of the foldable mobile device (M). The pad part (500) absorbsthe force from the outside that may impact the folding case (C). The padpart (500) may be made of the substance that has a tight adhesive forceand elasticity. Thereby, it may protect the foldable mobile device (M)more effectively, and prevent it from minute damages. If the case isdirectly contacted with the foldable mobile device (M) without the padpart (500), it cannot absorb the impact effectively. Furthermore, thedirect contact of the case may cause scratches on the foldable mobiledevice (M). The pad part (500) according to an embodiment of the presentinvention absorbs the impact effectively by allowing the case tomaintain a distance from the foldable mobile device (M). Also, the padpart (500) protects the foldable mobile device (M) from the scratches,and at the same time, it improves the tight adhesive force to reduce thegap between the foldable mobile device (M) and the case.

The folding case (C) according to an embodiment of the present inventioncomprises air rooms (400). The air rooms (400) absorb the impact to thefolding case (C) from one side covering the corner of the foldablemobile device (M). The air rooms (400) are formed at the portion thatmeets the corner of the foldable mobile device (M). The air rooms areformed at the portion that meets the corner of the first body (10) forthe first case (100), and at the portion that meets the corner of thesecond body (20) for the second case (200). When a case encounters animpact from outside, the empty space of the air rooms (400) minimizesthe physical force that would be directly delivered to the foldablemobile device (M). Since the corner portion of the device is prone todamage, the present invention provides a secondary protection to thefoldable mobile device (M) by the air rooms (400) in addition to theprimary protection by the case.

The folding case (C) according to an embodiment of the present inventionmay be made of hard material and soft material. By combining the hardand soft material, the folding case (C) may have both properties: aresistance from the impact and a absorbance of the impact. Especially,the frame of the first case (100) and the second case (200) is made ofsoft material to absorb the impact to the case. Depending on theembodiments, polycarbonate as the hard material and TPU (ThermoplasticPolyurethane) as the soft material, respectively, may be used. However,if the properties are satisfied, the materials for the first case (100)and the second case (200) are not limited to the material above. Thedouble injection moulding may be used to combine the hard material andthe soft material.

FIGS. 5 and 6 shows the first case (100) and the side cover (300) of afolding case (C) according to an embodiment of the present invention.According to the FIGS. 5 and 6 , the side cover (300) rotates along therotation axis of the first case (100). The side cover (300) rotates froma first position to a second position. FIG. 5 shows the side cover (300)in the first position, and FIG. 6 shows the side cover (300) in thesecond position after rotation. The first position is the state that theside cover (300) is closed, and the second position is the state thatthe side cover (300) is open as wide as possible.

FIG. 7 shows a bottom sectional view of a folding case according to anembodiment of the present invention. The side cover (300) rotates withan angle corresponding to the angle as the foldable mobile device (M) isfolded or unfolded. The side cover (300) is able to rotate with an anglethe same or wider than the angle that the foldable mobile device (M)rotates. It is because, if the angle that the side cover (300) rotatesis smaller than the angle that the foldable mobile device (M) rotates,the side cover (300) may interfere with the folding or unfolding of thefoldable mobile device (M). According to FIG. 7 , the angle between thefirst position and the second position may be from 87° to 93°.Preferably, the angle between the first position and the second positionmay be from 88.3° to 90°. It is derived by the repetitive simulation,and it corresponds to the optimal angle that the side cover (300) couldrespond to the angle that the foldable mobile device is folded orunfolded. Depending on the embodiments, the angle between the firstposition and the second position could be established depending on therotatable angle of the foldable mobile device.

FIG. 8 demonstrates a detailed connecting structure between a first case(100) and a side cover (300) of a folding case (C) according to anembodiment of the present invention. According to FIG. 8 , the foldingcase (C) according to an embodiment of the present invention comprisesan elastic part (120). The first case also comprises a support (150).The elastic part (120) provides an elastic force that enables the sidecover (300) to return to the first position. The elastic part (120) islocated at one side of the first case (100), and connected to the sidecover (300). The elastic part (120) enables the side cover (300) torotate along with the rotation axis of the first case (100), and toreturn back to the first position. The support (150) fixes or supportsat least a portion of the elastic part (120). More specifically, whileat least a portion of the elastic part (120) is supported by the support(150), the elastic force that enables the side cover (300) to rotateback to the first position along with the rotation axis of the firstcase (100) is delivered to the side cover (300) that is connected to theelastic part (120).

Meanwhile, the support (150) functions that the first case (100) is notto be pushed back or distorted. If the edge part (110) of the first case(100) is thin enough not to interfere with the display module of thefoldable mobile device (M), it is easy to be pushed back or distorted bythe force applied to the fold case. However, since the support (150)fixes or supports one side of the edge part (110), the first case (100)is more stably installed on the first body (10), and protects thefoldable mobile device (M). Preferably, the support (150) is made ofsteel. However, it is not limited to the aforementioned material, butvarious materials that satisfy the requirements for the strength tosupport the elastic part (120) and the first case (100) could be used.

Hereinafter, an embodiment that includes a spring in the elastic part(120) is described. The feature in the elastic part (120) is not limitedto the spring, but various components that provide an elastic forcecould also be considered.

The elastic part (120) comprises a pair of torsion springs separatedapart while being connected by an arm. The pair of torsion springscomprises a first torsion spring (121) and a second torsion spring(123). The first torsion spring (121) and the second torsion spring(123) are positioned in parallel. That is, a pair of torsion springsseparated apart in parallel, while being connected by an arm. The pairof torsion springs are connected to each other with a first arm, while asecond arm is connected to the side cover (300).

The elastic part (120) comprises a ring part (125). The ring part (125)is formed by a pair of torsion springs that are connected to each otherby an arm. In an embodiment of FIG. 8 , the first arm of a pair oftorsion springs are connected to each other to form the ring part (125).Although the ring part (125) in FIG. 8 is linear, the ring part (125)may include any shape of the arm that connects a pair of torsion springsseparated apart.

The side cover (300) comprises a protrusion (310) which has a pin hole(311). A pin (130) is inserted inside the pin hole (311), which enablesthe side cover (300) to rotate along with the rotation axis of the firstcase (100). The pin (130) is inserted into the pin hole (311) located atthe rotation axis of the first case (100), and functions as a shaft forthe rotation axis of the side cover (300). The first case (100)comprises a pin groove (140), which is connected to a coil of theelastic part (120). The pin (130) is inserted inside the coil from thepin groove (140).

FIG. 9 shows a support of a folding case according to an embodiment ofthe present invention. According to the FIG. 9 , the support (150)comprises a closure (151). The closure (151) covers one side of the pingroove (140). Thus, the closure (151) functions to prohibit the pin(130) falling off the pin hole (311) and the coil. The pin (130) isinserted inside the coil and the pin hole (311), while being covered bythe closure (151), and functions as a shaft for the rotation axis of theside cover (300). Thus, the side cover (300) may rotate by the hingelinkage to the first case (100).

FIG. 10 demonstrates steps of connection between a first case (100) anda side cover (300) of a folding case (C) according to an embodiment ofthe present invention. According to FIG. 10 , the elastic part (120) isfirst located at one side of the first case (100). Next, the protrusion(310) of the side cover (300) is placed at the elastic part (120), inbetween the pair of torsion springs. Then, the pin (130) is insertedinside the coil of the elastic part (120) and the pin hole (311) of theprotrusion (310) from the pin groove (140). When the support (150) isengaged on to the elastic part (120), the pin (130) inside does not falloff from the position by the closure (151). The support (150) could beplaced on the first case (100) by the linkage part (160). In anembodiment, the linkage part (160) links the support (150) to the firstcase (100) with a screw linkage. However, the linkage part (160) mayalso link the support (150) to the first case (100) in various waysother than the screw linkage.

FIG. 11 shows a folding case (C) in a closed state according to anembodiment of the present invention. FIGS. 12 and 13 show a folding case(C) in an open state according to an embodiment of the presentinvention. The side cover (300) rotates back to the first position bythe elastic part (120). As demonstrated in FIG. 11 , the side cover(300) maintains the first position by the elastic force of the elasticpart (120) when the folding case (C) is in a closed state by thefoldable mobile device being folded. As in FIGS. 12 and 13 , when thefolding case (C) is in a open state by the foldable mobile device (M)unfolded, the side cover (300) tends to rotate back to the firstposition by the elastic force generated by the elastic part (120)twisted while the side cover (300) is supported by the support (150).According to FIGS. 12 and 13 , the side cover (300) rotates withcontacting tightly one side of the second case (200) by the elasticforce of the elastic part (120). As a result, the side cover (300)protects the hinge part (30), while rotating, by contacting tightly thesecond case (200) when the foldable mobile device (M) becomes folded orunfolded.

The degree of contact between the side cover (300) and the second case(200) is adjustable by the arm angle of the torsion spring in theelastic part (120). It is because the elastic force is dependent on thearm angle of the torsion spring. If the elastic force is too strong, itmakes it hard to open the fold case (C) since it is difficult to openthe side cover (300). On the other hand, if the elastic force is tooweak, the hinge part (30) of the foldable mobile device (M) could beexposed or there would be a space between the side cover (300) and thesecond case (200) since the side cover (300) could not tightly contactto the second case (200). Thus, it is important to maintain the optimalelastic force that enables the side cover (300) to contact the secondcase while rotating. In an embodiment of the present invention, the armangle of the torsion springs is 180°, but it can be modified dependingon the elastic force.

FIG. 14 shows a bottom sectional view of a folding case (C) according toan embodiment of the present invention. Each of the side cover (300) andthe second case (200) comprises a curve (330, 220). The curve (330) ofthe side cover (300) is formed in a round shape at one corner thatcontacts the second case (200). Similarly, the curve (220) of the secondcase (200) is formed in a round shape at one corner that contacts theside cover (300). If the curves (330, 220) are not implemented at theportion where the side cover (300) and the second case (200) contacteach other, the side cover (300) is not able to rotate over the secondcase (200) smoothly. As in FIG. 14 , since the curves (330, 220) areimplemented at the portion where the side cover (300) and the secondcase (200) contact each other, the portion where they contact is notplane-to-plane, but point-to-point, which makes the side cover (300)rotate over the second case (200) easier. In an embodiment, the R valueof the curve (330) of the side cover (300) is larger than the R value ofthe curve (220) of the second case (200). The R value is a radius orrounding value, and it defines how much the corner is rounded. If the Rvalue of the curve (330) of the side cover (300) is larger, the sidecover (300) is able to rotate over the curve (220) of the second case(200) easier. Thus, when the foldable mobile device (M) is unfolded, itmay provide the users with convenience that comes from smooth rotationof the side cover (300) over the second case (200).

In an embodiment, the R value of the curve (330) of the side cover (300)may be from 1 mm to 3 mm, and the R value of the curve (220) of thesecond case (200) may be from 0.5 mm to 2.5 mm. However, each R valuecould have a different value with the condition that the R value of thecurve (330) of the side cover (300) is larger than the R value of thecurve (220) of the second case (200).

FIG. 15 demonstrates that a side cover (300) of a folding case (C) isused as a stand according to an embodiment of the present invention.According to FIG. 15 , the side cover (300) may function as a stand.Depending on the position of the hinge part (30), the foldable mobiledevice (M) could be fixed in a position that it is folded or unfolded ina certain degree of angle. The side cover (300) rotates while thefoldable mobile device (M) is unfolded, where it generates a heightdifference from the surface of the first case (100). Due to such heightdifference, the foldable mobile device (M) may be in a higher positionwith the fold case (C), compared to without the fold case. Thus, theside cover (300) may provide various angles of the stand depending onthe degree of folding or unfolding of the foldable mobile device (M).

FIG. 16 shows a button part of a folding case (C) according to anembodiment of the present invention. According to FIG. 16 , the firstcase (100) comprises a first button part (170), and the second case(200) comprises a second button part (230). The button part may have agroove or an opening at one side of the first case (100) and the secondcase (200), in order to press the button of the foldable mobile device(M) easily. In an embodiment of FIG. 16 , the first case (100) has agroove on one side, while the second case (200) has an opening on thecorresponding side. However, the button part may have variouscombinations of the groove and the opening, not limited to the above,depending on the exterior design or the arrangement of the buttons ofthe foldable mobile device (M).

When the foldable mobile device (M) is in a folded state, the anglebetween each side of the first button part (170) and the second buttonpart (230) has a certain degree of angle. Depending on the embodiments,a foldable mobile device (M) may comprise a module or a button forverification that requires a direct contact with a body part of a user.If such a module or a button for verification is included, at least aportion of the button part should be open to allow the direct contact.However, on the other hand, as the display of a foldable mobile device(M) gets larger, it becomes more difficult to implement the feature ofan opening as the edge part (110) gets thinner so as not to interferewith the display. It is because, if the area of the opening on the edgepart (110) becomes larger, it gets harder to maintain the durability ofa case. In order to maintain the durability of a case, one of the firstbutton part (170) and the second button part (230) is open, and theother is formed as a groove. However, if only one of the first buttonpart (170) and the second button part (230) has an opening, it is noteasy to press the button. The present invention forms a certain degreeof angle on one side of the button part of the first case (100) and thesecond case (200) to facilitate the direct contact to the module orbutton for verification of the foldable mobile device (M). By theformation of the designated degree of angle, it spontaneously leads thebody part to the button part. Therefore, the present invention may allowusers to press the button more easily due to the angle of the buttonpart, while maintaining the durability of the folding case (C).

When the foldable mobile device (M) is in a folded state, the anglebetween each side of the first button part (170) and the second buttonpart (230) may be from 150° to 160°, and preferably, 155°. It is derivedby the repetitive simulation, and it corresponds to the angle thatprovides the convenience for a user to easily contact the module or thebutton for verification.

The present invention, different from the previous folding cases,provides the full protection up to the corner of the hinge part (30),and at the same time, the portion that protects the hinge part (30)while the folding case (C) is folded or unfolded without any unfavorablespace or gap. Therefore, the present invention provides a full covercase that protects the entire foldable mobile device (M). In particular,the side cover (300) of the present invention rotates with contactingtightly the second case (200) while the folding case (C) is folded orunfolded, and thereby, it provides the impression as if the first case(100) and the second case (200) form one united case. Also, the foldingcase (C) according to the embodiments of the present invention providesthe overall aesthetic appearance as the users would have the impressionas if those parts form one united case by the side cover (300) while thefirst case (100) and the second case (200) are separated.

The description of the present invention as above is an exemplarydisclosure, and a skilled person in the art may be able to carry out thepresent invention with an obvious modification in various ways.Therefore, the scope of protection of the present invention is notlimited to the description and expression of embodiments. While theinvention has been shown and described with reference to differentembodiments thereof, it will be appreciated by those skilled in the artthat variations in form, detail, compositions and operation may be madewithout departing from the spirit and scope of the invention as definedby the accompanying claims.

The numbers and symbols used in the description and in the figures forthe present invention are summarized below:

-   -   C: a folding case;    -   10: a first body;    -   20: a second body;    -   30: a hinge part;    -   100: a first case;    -   110: an edge part;    -   111: a tunnel;    -   120: an elastic part;    -   121: a first torsion spring;    -   123: a second torsion spring;    -   125: a ring part;    -   130: a pin;    -   140: a pin groove;    -   150: a support;    -   151: a closure;    -   160: a linkage part;    -   170: a first button part;    -   200: a second case;    -   210: a bulge part;    -   220: a curve;    -   230: a second button part;    -   300: a side cover;    -   310: a protrusion;    -   311: a pin hole;    -   320: a cover part;    -   330: a curve;    -   400: air rooms; and    -   500: a pad part.

What is claimed is:
 1. A case for a foldable mobile electronic device,the case comprising: a first case; a second case; a side coverconnecting the first case and the second case and configured to rotatefrom a first position to a second position along with a rotation axis ofthe first case; and an elastic part providing an elastic force thatenables the side cover to return to the first position, wherein the sidecover is configured to rotate as the foldable mobile device is folded orunfolded, wherein the first case comprises a support that fixes at leasta portion of the elastic part, wherein the elastic part comprises a pairof torsion springs connected by an arm, and wherein the pair of torsionsprings that are connected to each other by the arm forms a ring part.2. The case of claim 1, wherein the pair of torsion springs comprises afirst torsion spring and a second torsion spring that are positioned inparallel.
 3. The case of claim 1, wherein the side cover rotates back tothe first position with the ring part being supported by the support. 4.The case of claim 1, wherein an angle between the first position and thesecond position is from 87 degrees to 93 degrees.
 5. The case of claim1, wherein the side cover comprises a cover part configured to cover upto a corner of a hinge part of the foldable mobile device.
 6. The caseof claim 1, wherein the side cover comprises a curve that is formed in around shape at one corner thereof that contacts the second case.
 7. Thecase of claim 6, wherein the second case comprises a curve that isformed in a round shape at one corner thereof that contacts the sidecover.
 8. The case of claim 7, wherein an R value of the curve of theside cover is larger than an R value of the curve of the second case. 9.A case for a foldable mobile electronic device, the case comprising: afirst case; a second case; a side cover connecting the first case andthe second case and configured to rotate from a first position to asecond position along with a rotation axis of the first case; and anelastic part providing an elastic force that enables the side cover toreturn to the first position, wherein the side cover is configured torotate as the foldable mobile device is folded or unfolded, wherein thefirst case comprises a support that fixes at least a portion of theelastic part, wherein the elastic part comprises a pair of torsionsprings connected by an arm, wherein the side cover comprises aprotrusion which has a pin hole, wherein a pin is inserted inside thepin hole and the elastic part, which enables the side cover to rotatebased on the rotation axis of the first case, and wherein the protrusionis placed in between the pair of torsion springs.
 10. The case of claim9, wherein the first case comprises a pin groove that is connected to acoil of the elastic part, and wherein the pin is inserted inside thecoil from the pin groove.
 11. The case of claim 10, wherein the supportcomprises a closure that covers one side of the pin groove.
 12. A casefor a foldable mobile electronic device, the case comprising: a firstcase; a second case; a side cover connecting the first case and thesecond case and configured to rotate from a first position to a secondposition along with a rotation axis of the first case; and an elasticpart providing an elastic force that enables the side cover to return tothe first position, wherein the side cover is configured to rotate asthe foldable mobile device is folded or unfolded, wherein the first casecomprises a first button part that has a groove or an opening at oneside of the first case, and the second case comprises a second buttonpart that has a groove or an opening at one side of the second case, andwherein an angle between each side of the first button part and thesecond button part is from 150 degrees to 160 degrees when the foldablemobile device is in a folded state.